Passive optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. Passive optical networks are a desirable choice for delivering high speed communication data because they may not employ active electronic devices, such as amplifiers and repeaters, between a central office and a subscriber termination. The absence of active electronic devices may decrease network complexity and/or cost and may increase network reliability.
FIG. 1 illustrates an exemplary passive optical network 100. As shown in FIG. 1, the network 100 may include a central office 110 that connects a number of end subscribers 115 (also called end users 115 herein). The central office 110 may additionally connect to a larger network such as the Internet (not shown) and a public switched telephone network (PSTN). The various lines of the network can be aerial or housed within underground conduits (e.g., see conduit 105).
In general, the network 100 includes feeder distribution cables (e.g., main cable 120) associated at one end with the central office 110. The portion of network 100 that is closest to central office 110 is generally referred to as the F1 region, where F1 refers to the “feeder fiber” from the central office. The F1 portion of the network may include a feeder cable (i.e., an F1 distribution cable) having on the order of 12 to 48 fibers; however, alternative implementations may include fewer or more fibers. The network 100 also has an F2 portion that includes cables and components located in closer proximity to the subscriber/end users 115.
The network 100 also may include fiber distribution hubs (FDHs) 130 that receive fibers of the main cable 120 extending from splice locations 125 and that output one or more F2 distribution cables 122. In general, an FDH 130 is an equipment enclosure that may include a plurality of optical splitters (e.g., 1-to-8 splitters, 1-to-16 splitters, or 1-to-32 splitters) for splitting the incoming feeder fibers into a number (e.g., 216, 432, etc.) of output distribution fibers corresponding to the F2 distribution cables 122. The F2 distribution cables are routed from the FDH 130 to locations in close proximity to the end users 115.
The network 100 typically includes a plurality of breakout locations 116 at which branch cables (e.g., drop cables, stub cables, etc.) are separated out from or optically coupled to distribution cables 122. Breakout locations 116 also can be referred to as tap locations or branch locations and branch cables also can be referred to as breakout cables or tethers. At a breakout location, fibers of the distribution cable can be broken out and connectorized to form a connectorized tether. In other embodiments, fibers of the distribution cable can be broken out and spliced to a length of optical fiber having a connectorized free end so as to form a connectorized tether.
Stub cables are typically branch cables that are routed from breakout locations 116 to intermediate access locations 104, such as a pedestals, drop terminals or hubs. Intermediate access locations 104 can provide connector interfaces located between breakout locations 116 and the subscriber locations 115. A drop cable is a cable that typically forms the last leg to a subscriber location 115. For example, drop cables can be routed from intermediate access locations 104 to subscriber locations 115. Drop cables also can be routed directly from breakout locations 116 to subscriber locations 115, thereby bypassing any intermediate access locations 104.
In certain embodiments, factory integrated terminations may be used at the F1 and/or the F2 region to provide environmentally sound and cost effective splicing protection. Factory integrated terminations refer to the use of factory integrated access (tap) points at specified locations, such as at breakout locations 116, in the network 100 instead of field installed splices. These breakout locations 116 may include connectorized tethers optically connected to the main cable at the factory. The manufacture of distribution cable having factory integrated termination is a time intensive process due to the large number of splices that are typically made, the significant testing that is typically performed for each splice, and the overall quantity of material handling and assembly that is typically required. It is desirable to provide manufacturing methods and manufacturing equipment that promote the efficient manufacture of distribution cable having factory installed branch lines.